Santa Clara valley aquifer
Encyclopedia
The Santa Clara valley aquifer is a groundwater aquifer
located in the southern San Francisco Bay Area
. The geology of the Santa Clara valley aquifer consists of a complex stratigraphy
of permeable and impermeable units. Management of aquifer resources is associated with the Santa Clara Valley Water District
.
levels dropped by as much as 200 ft (61 m). The decreasing pressure heads resulted in land subsidence of up to 15 ft (4.6 m). Recent work has shown that refined management practices have halted land subsidence.
.
Aquifer
An aquifer is a wet underground layer of water-bearing permeable rock or unconsolidated materials from which groundwater can be usefully extracted using a water well. The study of water flow in aquifers and the characterization of aquifers is called hydrogeology...
located in the southern San Francisco Bay Area
San Francisco Bay Area
The San Francisco Bay Area, commonly known as the Bay Area, is a populated region that surrounds the San Francisco and San Pablo estuaries in Northern California. The region encompasses metropolitan areas of San Francisco, Oakland, and San Jose, along with smaller urban and rural areas...
. The geology of the Santa Clara valley aquifer consists of a complex stratigraphy
Stratigraphy
Stratigraphy, a branch of geology, studies rock layers and layering . It is primarily used in the study of sedimentary and layered volcanic rocks....
of permeable and impermeable units. Management of aquifer resources is associated with the Santa Clara Valley Water District
Santa Clara Valley Water District
The Santa Clara Valley Water District provides stream stewardship, wholesale water supply and flood protection for Santa Clara County, California, in the southern San Francisco Bay Area. The district encompasses all of the county’s and serves the area’s 15 cities, 1.7 million residents and more...
.
History
The first half of the 20th century saw groundwater extraction increase with the increasing regional population of the Bay Area. Between 1912 and 1966 artesian pressurePressure head
Pressure head is a term used in fluid mechanics to represent the internal energy of a fluid due to the pressure exerted on its container. It may also be called static pressure head or simply static head...
levels dropped by as much as 200 ft (61 m). The decreasing pressure heads resulted in land subsidence of up to 15 ft (4.6 m). Recent work has shown that refined management practices have halted land subsidence.
Hydrogeology
Well core data indicate that the Santa Clara valley aquifer consists of between four to six different water bearing units. The aquifer is composed of both confined and unconfined units. Water bearing units are generally coarse-grained and separated by relatively fine-grained units. The thicknesses of coarse-grained sections vary between 10 and 25 ft (3 and 7.6 m) in the southeast and between 50 and 200 ft (15.2 and 61 m) in the south-central and southwestern areas of the valley. Temperature data from monitoring wells indicate that horizontal groundwater flow occurs primarily above 775 ft (236.2 m) in southern-central regions and above 510 ft (155.4 m) in southeastern areas.Management
Stream stewardship, wholesale water supply and flood protection for Santa Clara County, California is provided by the Santa Clara Valley Water DistrictSanta Clara Valley Water District
The Santa Clara Valley Water District provides stream stewardship, wholesale water supply and flood protection for Santa Clara County, California, in the southern San Francisco Bay Area. The district encompasses all of the county’s and serves the area’s 15 cities, 1.7 million residents and more...
.